Both are induced as mitokines in different mouse models of skeletal muscle dysfunction such as the Deletor mouse, a model for mitochondrial myopathy [15] and UCP1-transgenic (tg) mice displaying metabolic adaptations and altered daily fluctuations of substrate metabolism driven by slight skeletal muscle mitochondrial uncoupling [12, 16, 17]. This evidence concerns the gene UCP1 and Mitochondrial myopathy.